OUTLINE: This is a multicenter study. Patients are stratified according to baseline vitamin D (sufficient [≥ 30 ng/mL or ≥ 75 mmol/L] vs insufficient [< 30 ng/mL or < 75 mmol/L]) and institutional random periareolar fine-needle aspiration (RPFNA) status (performs RPFNA vs does not perform RPFNA). Patients are randomized to 1 of 2 treatment arms.